Rule chaining not working with Promise.all

まず issue の Promise.all の例を再現し、次に Engine.run と almanac.addRuntimeFact で使用されている runtime-fact の処理を調査します。samuel、joseph、anthony に対して、並列実行が逐次実行時と一致する対応する結果とイベントを生成すれば完了です。

If I run the engine sequentially, I am getting the desired result. If I run it in parallel, I am getting results only for the first run.

student-fav-subject.js

const { Engine } = require("json-rules-engine");

const apiClient = require("./student-api-client");

let engine = new Engine();

async function start() {
  let mathematicsSubjectRule = {
    conditions: {
      all: [
        {
          fact: "student-information",
          operator: "contains",
          value: "Mathematics",
          path: "$.subjects",
        },
      ],
    },
    event: { type: "studies-mathematics" },
    priority: 10,
    onSuccess: async function (event, almanac) {
      almanac.addRuntimeFact("studiesMathematics", true);
    },
    onFailure: function (event, almanac) {
      almanac.addRuntimeFact("studiesMathematics", false);
    },
  };
  engine.addRule(mathematicsSubjectRule);

  let physicsFavoriteRule = {
    conditions: {
      all: [
        {
          fact: "studiesMathematics",
          operator: "equal",
          value: true,
        },
        {
          fact: "student-information",
          operator: "equal",
          value: "Physics",
          path: "$.favoriteSubject",
        },
      ],
    },
    event: {
      type: "physics-favorite-subject",
      params: {
        message: " has Physics as their favorite subject",
      },
    },
  };

  engine.addRule(physicsFavoriteRule);

  engine.addFact("student-information", function (params, almanac) {
    console.log("loading student information...");
    return almanac.factValue("studentName").then((studentName) => {
      return apiClient.getStudentInformation(studentName);
    });
  });

  engine.on("success", (event, almanac, ruleResult) => {
    almanac.factValue("studentName").then((studentName) => {
      switch (event.type) {
        case "physics-favorite-subject":
          console.log(
            studentName,
            "HAS".green,
            "Physics as their favorite subject"
          );
      }
    });
  });

  engine.on("failure", (event, almanac, ruleResult) => {
    almanac.factValue("studentName").then((studentName) => {
      switch (event.type) {
        case "physics-favorite-subject":
          const studiesMathResult = ruleResult.conditions.all.find(
            (condition) => condition.fact === "studiesMathematics"
          );
          if (studiesMathResult) {
            if (studiesMathResult.result) {
              console.log(
                studentName,
                "DOES NOT".red,
                "have Physics as favorite subject"
              );
            } else {
              console.log(
                studentName,
                "CANNOT NOT".red,
                "have Physics as favorite subject as they do not study Mathematics"
              );
            }
          }
      }
    });
  });

  Promise.all([
    engine.run({ studentName: "samuel" }),
    engine.run({ studentName: "joseph" }),
    engine.run({ studentName: "anthony" }),
  ]);

  // await engine.run({ studentName: "samuel" });
  // await engine.run({ studentName: "joseph" });
  // await engine.run({ studentName: "anthony" });
}

start();

student-api-client.js

"use strict";

require("colors");
const fs = require("fs");

let studentData = require("./student-data.json");

/**
 * mock api client for retrieving student information
 */
module.exports = {
  getStudentInformation: (studentName) => {
    const message = 'loading student information for "' + studentName + '"';
    console.log(message.dim);
    return new Promise((resolve, reject) => {
      setImmediate(() => {
        resolve(studentData[studentName]);
      });
    });
  },
};

student-data.json

{
  "john": {
    "favoriteSubject": "Mathematics",
    "subjects": ["Physics", "Mathematics"]
  },
  "anthony": {
    "favoriteSubject": "Physics",
    "subjects": ["Physics", "Mathematics"]
  },
  "george": {
    "favoriteSubject": "History",
    "subjects": ["History", "Mathematics"]
  },
  "samuel": {
    "favoriteSubject": "Physics",
    "subjects": ["Physics", "History", "Geography", "Chemistry"]
  },
  "joseph": {
    "favoriteSubject": "Economics",
    "subjects": ["Economics", "Mathematics", "History"]
  }
}

Output

Running sequentially

loading student information...
loading student information for "samuel"
samuel CANNOT NOT have Physics as favorite subject as they do not study Mathematics
loading student information...
loading student information for "joseph"
joseph DOES NOT have Physics as favorite subject
loading student information...
loading student information for "anthony"
anthony HAS Physics as their favorite subject

Running parallelly (Promise.all)

loading student information...
loading student information...
loading student information...
loading student information for "samuel"
loading student information for "joseph"
loading student information for "anthony"
samuel CANNOT NOT have Physics as favorite subject as they do not study Mathematics